Light-emitting device and production method for synthetic resin globe for said light-emitting device

Abstract

A synthetic resin globe for a light-emitting device is produced by molding an intermediate product with an injection molding die, softening the intermediate product in a heating apparatus, expanding it with compressed air in a die to form a globe shape, transferring a concavo-convex shape formed in a core of the injection molding die to form a concavo-convex shape on an inner wall of the intermediate product, so that the concavo-convex shape can be easily formed into a desired shape in a lower part of an inner wall of the globe.

The invention claimed is: 
     
       1. A light-emitting device comprising:
 a base; 
 a semiconductor light-emitting element mounted on the base; 
 a globe covering the base and the semiconductor light-emitting element; 
 a reflection plate, above the semiconductor light emitting element and covered by the globe, positioned to direct light generated by the semiconductor light-emitting element to a lower position of the globe lower than the reflection plate, and not to reflect the light generated by the semiconductor light-emitting element to an upper position of the globe higher than the reflection plate; and 
 a concavo-convex part located on the globe only at the lower position of the globe lower than the reflection plate, wherein 
 the reflection plate comprises a first reflection plate and a second reflection plate, 
 the first reflection plate is positioned directly above the semiconductor light-emitting element, 
 the second reflection plate is provided separately from the first reflection plate and positioned above the first reflection plate, and 
 the first reflection plate has a window part as an opening in the reflection plate, and a light emitted from the semiconductor light-emitting element goes to the second reflection plate through the first reflection plate via the window part. 
 
     
     
       2. The light-emitting device according to  claim 1 , comprising a plurality of said semiconductor light emitting element, wherein
 the first reflection plate is arranged corresponding to each of the semiconductor light-emitting elements. 
 
     
     
       3. The light-emitting device according to  claim 1 , further comprising a heat sink which includes a portion positioned under the base and a portion positioned under the globe. 
     
     
       4. The light-emitting device according to  claim 1 , wherein
 a height of the concavo-convex part is 0.1 mm or less from the inner wall of the globe. 
 
     
     
       5. The light-emitting device according to  claim 1 , wherein
 the concavo-convex part comprises a first concavo-convex part and a second concavo-convex part provided on the first concavo-convex part. 
 
     
     
       6. The light-emitting device according to  claim 5 , comprising a plurality of the first and second concavo-convex parts, wherein
 the second concavo-convex parts are provided on the first concavo-convex parts, respectively. 
 
     
     
       7. The light-emitting device according to  claim 5 , wherein
 the first concavo-convex part and the second concavo-convex part each have a spherical shape. 
 
     
     
       8. The light-emitting device according to  claim 7 , wherein
 a height of the second concavo-convex part is 0.15 mm or less from a surface of the first concavo-convex part. 
 
     
     
       9. The light-emitting device according to  claim 3 , wherein:
 the globe includes an insertion part inserted in the heat sink and having an outer wall with a stepped part; and 
 a thickness of the stepped part is smaller than a thickness of the globe. 
 
     
     
       10. The light-emitting device according to  claim 9 , wherein
 the stepped part is provided between a light passage part of the globe and the insertion part. 
 
     
     
       11. The light-emitting device according to  claim 9 , wherein
 a thickness of a lower part of the stepped part is smaller than ⅔ of a thickness of an upper part of the stepped part. 
 
     
     
       12. The light-emitting device according to  claim 9 , wherein
 a thickness of a lower part of the stepped part is 0.4 mm or more. 
 
     
     
       13. The light-emitting device according to  claim 1 , wherein
 a side surface part of the globe corresponding to a position of the semiconductor light-emitting element expands outward, 
 a part of the globe positioned above the semiconductor light-emitting element has a spherical shape, and 
 a shape of the globe is front-back and left-side symmetrical. 
 
     
     
       14. The light emitting device according to  claim 1 , wherein the concavo-convex part includes a semispherical shape or a Fresnel lens shape. 
     
     
       15. The light emitting device according to  claim 1 , wherein the concavo-convex part is on an inner wall of the globe. 
     
     
       16. A light-emitting device comprising:
 a base; 
 a semiconductor light-emitting element mounted on the base; 
 a globe covering the base and the semiconductor light-emitting element; 
 a reflection plate, above the semiconductor light emitting element and covered by the globe, which reflects light generated from the semiconductor light-emitting element; and 
 a concavo-convex part located on the globe only at a lower position of the globe lower than the reflection plate, 
 wherein a thickness of the globe at a higher position than the reflection plate is thinner than a combined thickness of the concavo-convex part and the globe at the lower position, 
 the reflection plate comprises a first reflection plate and a second reflection plate, 
 the first reflection plate is positioned directly above the semiconductor light-emitting element, 
 the second reflection plate is provided separately from the first reflection plate and positioned above the first reflection plate, and 
 the first reflection plate has a window part as an opening in the reflection plate, and a light emitted from the semiconductor light-emitting element goes to the second reflection plate through the first reflection plate via the window part. 
 
     
     
       17. The light emitting device according to  claim 16 , wherein the concavo-convex part is on an inner wall of the globe. 
     
     
       18. The light-emitting device according to  claim 1 , wherein the second reflection plate is positioned nearer a center of the globe than the first reflection plate. 
     
     
       19. The light-emitting device according to  claim 1 , wherein the first reflection plate reflects the light to a lower direction while the second reflection plate reflects the light to a lateral direction. 
     
     
       20. The light-emitting device according to  claim 1 , wherein a surface shape of the first reflection plate for reflecting the light is different from a surface shape of the second reflection plate for reflecting the light.